Refinishing a platform - restoring surface grit.
I've got a weightlifting platform that could use refinishing.
When I originally varnished it with a polyurethane/stain, I used the unfinished side of a 3/4" birch plywood sheet. It gave the platform a real nice, rough texture that had a lot of grip. Over time, that wore down to the point where it's almost slick. How do I restore that rough texture?
I've already tried sanding it down with a medium grit paper and giving it a new coat of polyurethane/stain, but that didn't do anything. Should I just try again with something rougher?
And yes, I'm actually holding that handstand. Get on my level.